Pro38 Bulletin - Forward Closure Failures

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wighty44 said:
Do you have a bulletin that shows pictures? If so can you post it, or a link to it?

The one I saw from CTI did not have any pictures. Instead it attempted to describe how one might determine a good vs. bad closure.
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Here is the link to the bulletin with photos. https://pro38.com/pdfs/Bulletin-Pro38_Forward_Clousre.pdf

I had a bunch of potentially affected closures in my hand at URRF last week and one known good one. I could not see any difference in surface texture even using a 10X magnifying loupe. Trying to "feel" the difference in smoothness did not work either as CTI applies O-ring grease which migrates onto the plastic closure when they insert these into the reload tube.

My J316 Pink CATO

P1070106 (Large).JPG DSC_9808 (Large).JPG P1070111 (Large).JPG P1070115 (Large).JPG P1070117 (Large).JPG P1070118 (Large).JPG
 
Titan II said:
See post #1
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Ugh! My bad.:facepalm: I did see that photo but it's been a very long 2 days... Nonetheless, I agree those photos are difficult at best to see differences. However, the photos that were sent to me are much clearer, and show both an end and a side view. Comparing the good vs. bad closures is much more distinctive.

I just don't want to release the photos until I get an opinion from CTI on their usefulness.
 
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WILDMANRS said:
I will not sell anymore 38's unless I tell you about the problem and you are willing to take the risk.
There is no way to mark effected reloads unless you are getting new stock in and I don't think anybody is right now at least not in any real quantity .
How did you identify your bad motors ?if you received any motors from us since December of last year you have suspect loads.
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THAT. That first statement right there is what I was looking for. So you're saying that you're sold out of your lot of CTI identified potential problem reloads? But that you suspect the affected loads might be a larger problem than first reported?

I identified my loads based on date (only 2 that I have anywhere near the date code) and the closures visually with the pictures in the bulletin. To me, the difference was pretty clear. Even my VERY non-technical wife was able to tell the difference side by side.

bobkrech said:
Folks, please read my following 2 posts in another thread.

https://www.rocketryforum.com/showthread.php?134434-CTI-38mm-CATO-Report&p=1599231#post1599231

https://www.rocketryforum.com/showthread.php?134434-CTI-38mm-CATO-Report&p=1599233#post1599233

Bob
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What if one were to remove the black powder ejection charge and put a small screw in place, then, say JB weld it in place?

Do you know if, as some have claimed, all Pro38 forward closures are interchangeable? If not, is there ANY interchangeability within the same propellant type, say, a blue 2g load and a blue 5g load?
 
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It is easy to spot the defective delays. Look at the photos in https://pro38.com/pdfs/Bulletin-Pro38_Forward_Clousre.pdf

At URRF3 I purchased a Pro38 5G I540 from Kenny at Performance Hobbies. He was aware of the CTI document on identifying defective delays. Because the date on the reload was on the do not use list, Kenny opened up the I540 reload package and sure enough it was obvious the delay was a defective one. Then he opened up another Pro38 G motor made in 2013, removed that delay and put it into the I540 reload I was purchasing. No questions, no hassle, great service. CTI is sending all of their vendors boxes of good delays FOR WARANTEE REPLACEMENTS. In a very short time you should be able to go to any CTI dealer and get a replacement delay AT NO COST.
 
bobkrech said:
It is easy to spot the defective delays. Look at the photos in https://pro38.com/pdfs/Bulletin-Pro38_Forward_Clousre.pdf

At URRF3 I purchased a Pro38 5G I540 from Kenny at Performance Hobbies. He was aware of the CTI document on identifying defective delays. Because the date on the reload was on the do not use list, Kenny opened up the I540 reload package and sure enough it was obvious the delay was a defective one. Then he opened up another Pro38 G motor made in 2013, removed that delay and put it into the I540 reload I was purchasing. No questions, no hassle, great service. CTI is sending all of their vendors boxes of good delays FOR WARANTEE REPLACEMENTS. In a very short time you should be able to go to any CTI dealer and get a replacement delay AT NO COST.
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[emoji106]
 
Today, we had a failure for a motor from a vendor that is not on the list. October date code.

Jim
 
Banzai88 said:
What if one were to remove the black powder ejection charge and put a small screw in place, then, say JB weld it in place?
Click to expand...

Personally I think I would keep it simple, remove the BP and screw in a Aeropack adapter for the MD retainer. https://www.aeropack.net/webstore/product.asp?productid=353243224569305

$12.00 and your done, no glue, pennies and you have a nice firm solid solution.

View attachment 295845View attachment 295846View attachment 295847View attachment 295848View attachment 295849View attachment 295850
 
I checked my motors for the "bad" forward closure/delay elements but spotted nothing. Mine were all very smooth and had no wavy lines that I could see.

My candyman, Bay Area Rocketry, buys his CTI from the Wildman and I might have bought motors from October and December 2015 batches...dunno as I don't track my purchases. I will start writing the purchase dates on the CTI tubing from here on out.
 
[At URRF3 I purchased a Pro38 5G I540 from Kenny at Performance Hobbies. He was aware of the CTI document on identifying defective delays. Because the date on the reload was on the do not use list, Kenny opened up the I540 reload package and sure enough it was obvious the delay was a defective one. Then he opened up another Pro38 G motor made in 2013, removed that delay and put it into the I540 reload I was purchasing. No questions, no hassle, great service. CTI is sending all of their vendors boxes of good delays FOR WARANTEE REPLACEMENTS. In a very short time you should be able to go to any CTI dealer and get a replacement delay AT NO COST.

So did you launch the I540? The delay from the "G" motor was interchangeable and worked properly?
 
djs said:
Tim- I have an I470WT that I got from you about 2 months ago that I was going to fly in a few weeks. According to the date code on the package, it was made in June 2015, which I think puts me in the clear. I'm not sure when you got this in, but I think checking the date codes would at least narrow down which ones are suspect.
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don't fly it. The date code means nothing
 
wighty44 said:
The date code on the motor shipping tube is not associated with the fwd closure failure issue. That date is the propellant casting date... :wink:
Click to expand...

Fine, but the point is that the motor was from a vendor that was not on the list of vendors that received bad motors.

Jim
 
wighty44 said:
Thanks. Just trying to help. Did you share that info with CTI?
Click to expand...

The vendor was not aware of the motor problem, having not been contacted by CTI (I presume because they didn't think they had shipped him affected motors). He will contact them Monday.

Jim
 
mpitfield said:
Personally I think I would keep it simple, remove the BP and screw in a Aeropack adapter for the MD retainer. https://www.aeropack.net/webstore/product.asp?productid=353243224569305

$12.00 and your done, no glue, pennies and you have a nice firm solid solution.

View attachment 295845View attachment 295846View attachment 295847View attachment 295848View attachment 295849View attachment 295850
Click to expand...

I don't think that will work. If the hot gasses are able to ignite the delay grain on the other end, it may blow up the closure.
 
It was certified with a non defective closure. So a malfunction could still be a problem.
 
Ravenex said:
It was certified with a non defective closure. So a malfunction could still be a problem.
Click to expand...

Sticking to the context of the discussion, based on how Bob described the issue, I highly doubt it.

This was designed as an adapter for the Aeropack MD retainer system, and in doing so it plugs the forward closure with positive mechanical retention. Positive as in screwed, self-tapped, into the forward closure with a socket wrench, and with a bit of force. So whether there is silicon mold release or super doper silicone mold release or the slipperiest substance known to mankind it would likely have very little effect on the retention. YMMV

Of course that is not what this was designed for, however if you are simply trying to plug the forward closure then this will do it and do it well. That is if the forward closure is not deformed, which would be another scenario all together and not what Bob described as the issue.
 
timbucktoo said:
Not true Bob! I quote from the bulletin "In a side by side comparison between bad & good forward closures it is extremely difficult to visually identify the difference."
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That IS what the bulletin says, but I truly believe that's what the lawyers told them to put in.

Have you looked at them yourself?

I found it easy and just like the bulletin. Even my non-rocketry wife could tell them apart. They look and feel different. The defective ones are VERY shiny, have the small ridges as shown in the picture (which you can feel with your finger nail), and feel "slippery". The normal closures look and feel like they're molded from the same stuff as the liner.
 
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Banzai88 said:
Have you looked at them yourself?
Click to expand...

I have looked at several and they have miniscule ridges, some shiny, some not but then I pulled out an old motor with a date stamp from 2013 and it feels the same but not shiny. So if it's shiny does thst mean defective?
 
timbucktoo said:
So if it's shiny does thst mean defective?
Click to expand...

If it's from October 2015(or maybe earlier) until now, I'd say almost certainly. I've opened 30 ish motors from 2013 to just before October 2015, and ALL of my fwd closure plastic is dull (like the 'good' ones in the bulletin). I only have 2 from the stated date range, and 1 is CLEARLY shiny and smooth, 1 is like the older ones.

I guess that the real problem is that the date code is the casting date of the propellent, and may not correlate well to the bulletin. To make matters worse, I have some motors from 2014 and 2015 that have 2 date stamps of them!

Hopefully CTI sorts this out sometime soon. It would be nice to have a blue date for the propellent, a red date for the closure, and a black date for packaging. In light of the nature of the product, I'm amazed that APCP motor manufacturers don't have process controls that could actually answer these questions.

I'd also like to have a definitive answer to the question "Are all Pro38 forward closures interchangeable?". If yes, that might change things and save some people's summer flying season.
 
Once again the date code on the reload means nothing for this problem.
If you received any pro38 reload from us since oct 2015 it is suspect.
We have not received any replacement closures yet or been told when they will be available .
 
mpitfield said:
Personally I think I would keep it simple, remove the BP and screw in a Aeropack adapter for the MD retainer. https://www.aeropack.net/webstore/product.asp?productid=353243224569305

$12.00 and your done, no glue, pennies and you have a nice firm solid solution.

View attachment 295845View attachment 295846View attachment 295847View attachment 295848View attachment 295849View attachment 295850
Click to expand...

The Adapter is not designed to function as a high pressure seal, because that is not necessary in a regular motor. At the time the delay usuallly burns through, the motor is already depressurized.

If the delay fails, while the motor is still under pressure, hot gases will probably find a way through imperfections in the mating surfaces and the thread (typical threads don't seal) and the still resulting delay blow by just got $12.00 more expensive.
In theory one could add a seal, but this will lead to further questions (e.g. How deep are the threads? Deep enough to result in a positive lock or are we talking mostly about friction that can be adversely influenced by the silicone additive?).

Reinhard
 
Banzai88 said:
If it's from October 2015(or maybe earlier) until now, I'd say almost certainly. I've opened 30 ish motors from 2013 to just before October 2015, and ALL of my fwd closure plastic is dull (like the 'good' ones in the bulletin). I only have 2 from the stated date range, and 1 is CLEARLY shiny and smooth, 1 is like the older ones.

I guess that the real problem is that the date code is the casting date of the propellent, and may not correlate well to the bulletin. To make matters worse, I have some motors from 2014 and 2015 that have 2 date stamps of them!

Hopefully CTI sorts this out sometime soon. It would be nice to have a blue date for the propellent, a red date for the closure, and a black date for packaging. In light of the nature of the product, I'm amazed that APCP motor manufacturers don't have process controls that could actually answer these questions.

I'd also like to have a definitive answer to the question "Are all Pro38 forward closures interchangeable?". If yes, that might change things and save some people's summer flying season.
Click to expand...
I don't think the shinny thing is the correct way to tell. They said that it is very difficult to spot the difference even side by side, that would be to easy.

Here is the real ironic thing they used to have 2 date codes on them but it was always confusing people and was never used so they did away with the delay code a few years ago.

I do not know if all delays are the same for all of 38 loads, I am waiting to hear back from CTI .
 
WILDMANRS said:
I don't think the shinny thing is the correct way to tell. They said that it is very difficult to spot the difference even side by side, that would be to easy.

Here is the real ironic thing they used to have 2 date codes on them but it was always confusing people and was never used so they did away with the delay code a few years ago.

I do not know if all delays are the same for all of 38 loads, I am waiting to hear back from CTI .
Click to expand...

Thanks Tim - I have laid several out & I really can't tell which is which. Just going to go by the invoice date and assume all are deffective!
 

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